The firearm barrels and projectiles of this invention function together in conjoint-action to form transiently captive environments in a series of recessed chambers of the bore walls by the interacting transitional interfacing functions of the projectile's lubricated bearing surfaces, furnished with a recessed co-chamber, and sequentially bearing against the caliber sized annularly segmented bore wall bearing surface interfaces and passing the mouths of explosively charged annular bore wall propellant gas-relief chambers, the said projectiles bearing surface interfaces thereby also functioning as quick-acting valves in combination with the annular segmented bore wall bearing surface interfaces as the projectile passes each said charged annularly recessed bore chamber's mouth; the said bore wall chambers becoming filled with explosive propellant charge portions forced from a propellant charge unconfined in the bore column in front of the projectile, and the said charge quickly sealed therein the said chambers by the projectile bore obturating body are ignited to explosively burn confined for short periods of time.
To avoid deleterious forces from acting on the barrel structure the mass of each charge portion impacting into bore wall chambers is preferably kept small, and the impaction fores widely distributed over as broad and shallow a longitudinal surface of a bore chamber's wall structure as practical to minimize said force of impaction and also naturally provides easy access to the chamber's structure when cleaning the bore after firing when necessary.
The said interfacing valving functions of the conjoint-action of the bearing surfaces of the projectile and segmented bore walls, in relative conjunction of structural configuration of their chambers, transiently create a series of small individual transitory constructed special captively sealed and confined explosively developing propellant environmental entities withing each of the said chambers recessed into the segmented bore walls of the firearm barrel shared by the said in transit captive co-chamber of the projectile; and these chambers of the bore and projectile can be put to use to cooperate in various ways and methods to meet the requirements of various firearms of particular ballistic character to create an efficient propellant property by the explosive development of high pressure propellant gases forming in and then suddenly relieved to expand out of said chambers directly at the projectile body which propel the projectile along the bore and may also act to impart a particular rotational movement to the projectile while resisting reactive recoiling forces acting on the firearm barrel.
In a particular alternative combination of a firearm barrel and a projectile with a front charge, the rearward chambers of the bore wall may be charged by the projectile and the forward chambers of the bore may be left devoid of charges, by early depletion of the projectile's front charge, and thereby the forward chambers only used as bore column gas expansion chambers to bring about reduction of bore column pressure while bore column expansive gas pressure still actively energizes the projectile movement along the bore, but with a relatively reduced muzzle blast as the projectile exits the barrel.
It is brought out that the plug of air contained in the front of projectiles in the bores of firearm barrels of known conventional construction is normally highly compressed and thereby heated in front of a speeding projectile fired along the bore in which the projectile acts as an obturator. This plug of air somewhat resists the projectile's progress and contributes heat transfer to the firearm barrel.
The phenomenon of this said highly compressed and heated plug of air in the bore is reduced in the firearm barrels of this invention and therefore relieves, to a certain degree, air resistance and its heat transfer to the barrel because as the projectile passes the mouths of the bore wall chambers the plug of air being compressed in front of the projectile in the bore is, before becoming highly compressed and heated, progressively passed captively into the series of said segmented bore wall chamber's mouths, being wedged therein by the projectile along with and between the grains of the front propellant charge of the projectile.
It is known that most modern smokeless gunpowders burn slowly when not confined relative to the explosive rate at which they burn when highly confined in the closed systems of the bore of a firearm barrel wherein the projectile body acts as a bore obturator to the expansive escape of the gaseous products of combustion of the gunpowder, and thereby the rising heat and pressure of the confined developing gases forces, with greater and greater efficiency, more and more heat into the remaining unburned gunpowder grains and causes them to burn more and more explosively as additional explosive propellant gases develop, and as the confined heat and pressure of the gases becomes higher and higher until eventually the projectile's inertia is overcome and moves substantially forward along the bore relieving its breech charge from high confinement.
These burning characteristics of smokeless gunpowder are taken and used to advantage by structures of the firearm barrels and projectiles of this specification.
In the firearms of known conventional closed-system structures that use a single or even multiple propellant charges in the chamber of the breech area of the barrel there is a rapid rate of increasing entropy where the expanding explosive force of the charge or charges becomes less and less efficient to act on the diametric short axis of the projectile thereto to push the projectile forwards as it speeds away from the breech in its course along the bore of a firearm barrel, because theoretically in accordance to certain laws of thermodynamics, hot propellant gases under pressure do not easily expand faster than the speed of sound and therefore the conventional firearms described in this paragraph do not have the potential to shoot projectiles much faster than 1.25 miles per second from the force of expanding propellant gases initiated from the chamber of the breech. That is, theoretically, once the projectile is traveling at its potential limit of 1.25 miles per second in the barrel the propellant gases no longer have the potential to expand any more rapidly from the barrel's explosive chamber of the breech end than the forwarded speed of the projectile they were expanding against, and therefore, kinetic energy is no longer available to be absorbed from the propellant gases by the projectile.
Prior inventions have introduced some closed structure firearm systems employing multiple charges in wells of the bore walls in attempts to reduce entropy, but the charges of these bore structures are shown not to be precisely controlled, modulated or otherwise structurally governed for exact timed development and finely tuned relief by and directly at the body of the projectile to energize its movement along the bore.